Add Webfinger

lib/nulla/activitypub.ex

@@ -89,7 +89,9 @@ defmodule Nulla.ActivityPub do
   def note(domain, note) do
     attachment =
       case note.media_attachments do
-      [] -> []
+        [] ->
+          []
+
         attachments ->
           [
             attachment:
@@ -151,8 +153,16 @@ defmodule Nulla.ActivityPub do
     )
   end
 
-  @spec following(String.t(), Nulla.Models.User.t(), Integer.t(), List.t(), Integer.t(), Integer.t()) :: Jason.OrderedObject.t()
-  def following(domain, user, total, following_list, page, offset) when is_integer(page) and page > 0 do
+  @spec following(
+          String.t(),
+          Nulla.Models.User.t(),
+          Integer.t(),
+          List.t(),
+          Integer.t(),
+          Integer.t()
+        ) :: Jason.OrderedObject.t()
+  def following(domain, user, total, following_list, page, offset)
+      when is_integer(page) and page > 0 do
     data = [
       "@context": "https://www.w3.org/ns/activitystreams",
       id: "https://#{domain}/@#{user.username}/following?page=#{page}",
@@ -194,8 +204,16 @@ defmodule Nulla.ActivityPub do
     )
   end
 
-  @spec followers(String.t(), Nulla.Models.User.t(), Integer.t(), List.t(), Integer.t(), Integer.t()) :: Jason.OrderedObject.t()
-  def followers(domain, user, total, followers_list, page, offset) when is_integer(page) and page > 0 do
+  @spec followers(
+          String.t(),
+          Nulla.Models.User.t(),
+          Integer.t(),
+          List.t(),
+          Integer.t(),
+          Integer.t()
+        ) :: Jason.OrderedObject.t()
+  def followers(domain, user, total, followers_list, page, offset)
+      when is_integer(page) and page > 0 do
     data = [
       "@context": "https://www.w3.org/ns/activitystreams",
       id: "https://#{domain}/@#{user.username}/followers?page=#{page}",
@@ -225,4 +243,17 @@ defmodule Nulla.ActivityPub do
 
     Jason.OrderedObject.new(data)
   end
+
+  def webfinger(domain, username, resource) do
+    Jason.OrderedObject.new(
+      subject: resource,
+      links: [
+        Jason.OrderedObject.new(
+          rel: "self",
+          type: "application/activity+json",
+          href: "https://#{domain}/@#{username}"
+        )
+      ]
+    )
+  end
 end

lib/nulla/key_gen.ex

@@ -5,8 +5,11 @@ defmodule Nulla.KeyGen do
     {:RSAPrivateKey, :"two-prime", n, e, _d, _p, _q, _dp, _dq, _qi, _other} = rsa_key
     public_key = {:RSAPublicKey, n, e}
 
-    private_entry = {:PrivateKeyInfo, :public_key.der_encode(:RSAPrivateKey, rsa_key), :not_encrypted}
-    public_entry  = {:SubjectPublicKeyInfo, :public_key.der_encode(:RSAPublicKey, public_key), :not_encrypted}
+    private_entry =
+      {:PrivateKeyInfo, :public_key.der_encode(:RSAPrivateKey, rsa_key), :not_encrypted}
+
+    public_entry =
+      {:SubjectPublicKeyInfo, :public_key.der_encode(:RSAPublicKey, public_key), :not_encrypted}
 
     private_pem = :public_key.pem_encode([private_entry])
     public_pem = :public_key.pem_encode([public_entry])

lib/nulla/models/user.ex

@@ -77,5 +77,7 @@ defmodule Nulla.Models.User do
     ])
   end
 
+  def get_user_by_username(username), do: Repo.get_by(User, username: username)
+
   def get_user_by_username!(username), do: Repo.get_by!(User, username: username)
 end

lib/nulla/utils.ex

@@ -32,15 +32,17 @@ defmodule Nulla.Utils do
         offset = (page - 1) * per_page
 
         query =
-          from [f, u] in
-            from(f in Follow,
-              join: u in User, on: u.id == f.target_id,
+          from(
+            [f, u] in from(f in Follow,
+              join: u in User,
+              on: u.id == f.target_id,
               where: f.user_id == ^user_id,
               order_by: [asc: u.inserted_at],
               offset: ^offset,
               limit: ^per_page,
               select: u
             )
+          )
 
         users = Repo.all(query)
 
@@ -73,7 +75,8 @@ defmodule Nulla.Utils do
         query =
           from f in Follow,
             where: f.target_id == ^user_id,
-            join: u in User, on: u.id == f.user_id,
+            join: u in User,
+            on: u.id == f.user_id,
             order_by: [asc: u.inserted_at],
             offset: ^offset,
             limit: ^per_page,

lib/nulla_web/controllers/follow_controller.ex

@@ -1,9 +1,9 @@
 defmodule NullaWeb.FollowController do
   use NullaWeb, :controller
-  alias Nulla.Models.User
-  alias Nulla.Models.InstanceSettings
   alias Nulla.ActivityPub
   alias Nulla.Utils
+  alias Nulla.Models.User
+  alias Nulla.Models.InstanceSettings
 
   def following(conn, %{"username" => username, "page" => page_param}) do
     instance_settings = InstanceSettings.get_instance_settings!()
@@ -11,11 +11,13 @@ defmodule NullaWeb.FollowController do
     offset = instance_settings.offset
     user = User.get_user_by_username!(username)
     total = Utils.count_following_by_username!(user.username)
+
     page =
       case Integer.parse(page_param) do
         {int, _} when int > 0 -> int
         _ -> 1
       end
+
     following_list = Utils.get_following_users_by_username!(user.username, page)
 
     conn
@@ -40,11 +42,13 @@ defmodule NullaWeb.FollowController do
     offset = instance_settings.offset
     user = User.get_user_by_username!(username)
     total = Utils.count_followers_by_username!(user.username)
+
     page =
       case Integer.parse(page_param) do
         {int, _} when int > 0 -> int
         _ -> 1
       end
+
     followers_list = Utils.get_followers_by_username!(user.username, page)
 
     conn

lib/nulla_web/controllers/note_controller.ex

@@ -1,9 +1,9 @@
 defmodule NullaWeb.NoteController do
   use NullaWeb, :controller
   alias Nulla.Repo
+  alias Nulla.ActivityPub
   alias Nulla.Models.Note
   alias Nulla.Models.InstanceSettings
-  alias Nulla.ActivityPub
 
   def index(conn, _params) do
     notes = Notes.list_notes()

lib/nulla_web/controllers/user_controller.ex

@@ -1,10 +1,10 @@
 defmodule NullaWeb.UserController do
   use NullaWeb, :controller
+  alias Nulla.ActivityPub
+  alias Nulla.Utils
   alias Nulla.Models.User
   alias Nulla.Models.Note
   alias Nulla.Models.InstanceSettings
-  alias Nulla.ActivityPub
-  alias Nulla.Utils
 
   def show(conn, %{"username" => username}) do
     accept = List.first(get_req_header(conn, "accept"))

lib/nulla_web/controllers/webfinger_controller.ex

@@ -0,0 +1,34 @@
+defmodule NullaWeb.WebfingerController do
+  use NullaWeb, :controller
+  alias Nulla.Repo
+  alias Nulla.ActivityPub
+  alias Nulla.Models.User
+  alias Nulla.Models.InstanceSettings
+
+  def show(conn, %{"resource" => resource}) do
+    case Regex.run(~r/^acct:([^@]+)@(.+)$/, resource) do
+      [_, username, domain] ->
+        case User.get_user_by_username(username) do
+          nil ->
+            conn
+            |> put_status(:not_found)
+            |> json(%{error: "Not Found"})
+
+          user ->
+            instance_settings = InstanceSettings.get_instance_settings!()
+
+            if domain == instance_settings.domain do
+              json(conn, ActivityPub.webfinger(domain, username, resource))
+            else
+              conn
+              |> put_status(:not_found)
+              |> json(%{error: "Not Found"})
+            end
+        end
+      _ ->
+        conn
+        |> put_status(:bad_request)
+        |> json(%{error: "Bad Request"})
+    end
+  end
+end

lib/nulla_web/router.ex

@@ -21,6 +21,8 @@ defmodule NullaWeb.Router do
   scope "/", NullaWeb do
     pipe_through :browser
 
+    get "/.well-known/webfinger", WebfingerController, :show
+
     get "/@:username", UserController, :show
     get "/@:username/following", FollowController, :following
     get "/@:username/followers", FollowController, :followers

priv/repo/migrations/20250527054942_create_instance_settings.exs

@@ -21,11 +21,14 @@ defmodule Nulla.Repo.Migrations.CreateInstanceSettings do
     execute(fn ->
       {public_key, private_key} = Nulla.KeyGen.generate_keys()
       now = NaiveDateTime.utc_now() |> NaiveDateTime.truncate(:second)
+
       domain =
         Application.get_env(:nulla, NullaWeb.Endpoint, [])
         |> Keyword.get(:url, [])
         |> Keyword.get(:host, "localhost")
+
       esc = fn str -> "'#{String.replace(str, "'", "''")}'" end
+
       sql = """
       INSERT INTO instance_settings (
         name, description, domain, registration,

priv/repo/migrations/20250530110822_create_users.exs

@@ -8,7 +8,7 @@ defmodule Nulla.Repo.Migrations.CreateUsers do
       add :password, :string
       add :is_moderator, :boolean, default: false, null: false
       add :realname, :string
-      add :bio, :string
+      add :bio, :text
       add :location, :string
       add :birthday, :date
       add :fields, :map